Framing corner joint and method of manufacture

ABSTRACT

A framing corner joint includes first and second framing rails of fiberglass-reinforced resin construction. The first and second framing rails have hollow mitered ends. A pair of thermoplastic plugs are received in the mitered ends of the respective framing rails. Each of the plugs includes a body inserted into the hollow interior of an associated framing rail and a flat plug flange at an angle of 45° to the body. The plug flanges extend outwardly from the peripheries of the bodies between the rail ends and have flat end faces that are bonded to each other. The bodies of the plugs preferably are hollow, and preferably are received by interference press-fit within the ends of the rails. The plug flanges of the plugs preferably are welded to each other.

The present disclosure relates to corner joints in framing structuresfor windows and/or doors for example, and to a method of making such acorner joint.

BACKGROUND AND SUMMARY OF THE DISCLOSURE

When joining the ends of lineal rails at the corners of structural sashand framing members of building windows, for example, the miteredcorners of the lineal rails can be thermally welded to each other whenthe rails are of vinyl construction. Fiberglass-reinforced compositerails have many advantages over vinyl, but cannot readily be welded toeach other. Mechanical joining has been used, increasing the cost of theframing corner and/or deleteriously affecting the sealing properties ofthe corner joint. One objective of the present disclosure is to providethe ability to weld the corners of a fiberglass-reinforced compositewindow or door framing to obtain the sealing benefits of a welded jointwhile retaining other benefits of using fiberglass-reinforcedcomposites.

The present disclosure involves a number of aspects that can beimplemented separately from or in combination with each other.

A framing corner joint in accordance with one aspect of the presentdisclosure includes first and second framing rails offiberglass-reinforced resin construction. The first and second framingrails have hollow mitered ends. A pair of thermoplastic plugs arereceived in the mitered ends of the respective framing rails. Each ofthe plugs includes a body inserted into the hollow interior of anassociated framing rail and a flat end wall at an angle of 45° to thebody. The end walls extend outwardly from the peripheries of the bodiesbetween the rail ends and have flat end faces that are bonded to eachother. The bodies of the plugs preferably are hollow, and preferably arereceived by interference press-fit within the ends of the rails. Onceinserted, the flanges of the two plugs preferably are welded to eachother to join that corner of the framing member.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure, together with additional objects, features, advantagesand aspects thereof, will best be understood from the followingdescription, the appended claims and the accompanying drawings, inwhich:

FIG. 1 is a front elevational view of a framing structure in accordancewith one exemplary embodiment of the present disclosure;

FIG. 2 is a fragmentary elevational view on an enlarged scale of theportion of FIG. 1 within the area 2;

FIG. 3 is a sectional view on an enlarged scale of the corner jointillustrated in FIG. 2;

FIG. 4 is a sectional view of the upper rail in FIG. 2 having the pluginserted therein; and

FIGS. 5-8 are views of the plug illustrated in FIG. 4.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 illustrates a building window assembly 20 in accordance with oneexemplary embodiment of the present disclosure. Window assembly 20includes an outer framing 22 that presents one type of framingstructure, an upper sash 24 that presents another type of framingstructure, and a lower sash 26 that presents a framing structure similarto upper sash 24. Upper sash 24 includes upper and lower framing rails28 and framing sides rails 30. Lower sash 26 may be of similarconstruction. Framing rails 28,30 are of elongated fiberglass-reinforcedresin construction having interiors of predetermined geometry andmitered ends at angles of 45° where the rails are joined to each other.At least the ends of the rails are open and hollow. The central portionsof the rails may be hollow, or may be filled with insulating materialsuch as polyurethane foam. The interiors of the rails are mirror imagesof each other at each corner.

FIGS. 2 and 3 illustrate a framing corner joint 32 in accordance with anexemplary embodiment of the present disclosure where an upper rail 28 isjoined to a side rail 30. A first plug 34 is assembled to the miteredend of rail 28, and a second plug 36 is assembled to the mitered end ofrail 30. Plug 34 has a body 38, which preferably is hollow to reducecost and is received within the hollow mitered end of rail 28. An endwall 40 closes one end of hollow body 38 and is disposed at an angle of45° to the axis of body 38. End wall 40 preferably is imperforate forstrength and rigidity, as best seen in FIGS. 5 and 8, althoughperforations or openings could be provided without departing from thepresent disclosure in its broadest aspects. End wall 40 preferablyextends outwardly from the periphery of body 38 to form a lip or flangethat overlies and abuts the end of rail 28 when plug 34 is fullyinserted into the end of the rail, as best seen in FIG. 4. The flange onthe plug provides a positive stop for the insertion of the plug into therail, although it is possible to insert the plug to the proper distancewithout the flange. In addition, the flange provides more surface areafor a bond between the rail members and excess material to assure a sealbetween the rail members, although it is possible to butt weld the plugswith just the edges of the plug walls and this can provide enough excessmaterial to provide the seal between the two rail members. Body 38 has aperipheral contour that corresponds with the predetermined interiorcontour of rail 28, and preferably is received by interference press-fitwithin the interior of rail 28. Adhesive or another suitable bonding orsealing agent may be applied to the outer surface of plug body 38 beforethe plug body is press-fitted into the interior of rail 28. Theperiphery of end wall 40 preferably follows the periphery of body 38 butextends radially outwardly therefrom so as to overlie and abut the endof rail 28 as previously described.

Plug 36 (FIG. 3) has a construction that is a mirror image of plug 34,with a hollow body 42 received within the interior of rail 30 and an endwall 44 that closes the end of hollow body 42. For simple railgeometries, plugs 34, 36 may be identical. For more complex railgeometries of the type illustrated in the drawings, plugs 34, 36 arenon-identical but are mirror images of each other along the planes ofend walls 40, 44. The geometry of plug 34 illustrated in FIGS. 5-8 forexample, accommodates strengthening ribs on the inside of the rail. Theperiphery of end wall 40 follows the periphery of body 38 with a slightradial flange or lip that corresponds to the thickness of the rail wall.Plugs 34, 36 are of respective one-piece thermoplastic constructionssuch as PVC, polyurethane or other weldable thermoplastic material.

After the plugs 34, 36 have been inserted into the respective rails 28,30, the end walls 40, 44 of plugs 34, 36 are welded or otherwise securedto each other. This may be carried out by thermal or solvent welding,for example. During this welding operation, the framing ends are heldtightly against each other. The flange portions of end walls 40,44 thatoverlie the ends of the respective rails are sources of excess materialthat can be pushed into the seam to create pressure to improve the bondaround the insides of the respective rails. This excess material canalso be pushed outside of the seam to create a watertight seal at theseam. Such excess material is preferred to help assure a good seal andtight bond to the framing rail, with excess material possibly beingpushed to the outside of the respective rails and trimmed after thewelding operation. Thermoplastic material will be exposed between theends of the respective rails, but will be as thin as possible dependingon the accuracy of the mitered cuts and the squareness of the assembly.The thermoplastic material will fill the gaps between the rail membersand is desired to be as thin as possible and preferably less than0.010″. The preferred embodiment would be where the mitered corners arecut perfectly and assembled squarely, and all of the thermoplasticmaterial is squeezed out from the joint leaving only a minuscule bondlayer.

There thus have been disclosed a framing corner joint and a method ofmaking a framing corner joint that fully satisfy all of the objects andaims previously set forth. The disclosure has been presented inconjunction with an exemplary embodiment, and a number of additionalmodifications and variations have been discussed. Other modificationsand variations readily will suggest themselves to persons of ordinaryskill in the art in view of the foregoing discussion. The disclosure isintended to embrace all such modifications and variations as fall withinthe spirit and broad scope of the appended claims.

1. A framing corner joint that includes: first and second framing railsof fiberglass-reinforced resin construction, said first and secondframing rails having hollow mitered ends, a pair of thermoplastic plugsreceived in said mitered ends of said rails, each of said plugsincluding a body inserted into the hollow end of an associated rail anda flat end wall at an angle of 45° to said body, said end wallsextending outwardly from peripheries of said bodies between said miteredends of said rails and having flat end faces that are bonded to eachother.
 2. The framing corner joint set forth in claim 1 wherein saidplugs are of constructions that are mirror images of each other.
 3. Theframing corner joint set forth in claim 1 wherein each of said plugbodies is received by interference press-fit within the associated railend.
 4. The framing corner joint set forth in claim 3 including asealing or bonding agent between said plug bodies and interior surfacesof said rails.
 5. The framing corner joint set forth in claim 3 whereinsaid plug bodies are hollow.
 6. The framing corner joint set forth inclaim 1 wherein said end walls are welded to each other.
 7. The framingcorner joint set forth in claim 6 wherein said end walls areimperforate.
 8. A framing corner joint that includes: first and secondframing rails of fiberglass-reinforced resin construction, said firstand second framing rails having interiors of predetermined mirror-imagecontours and hollow mitered ends, a pair of thermoplastic plugs receivedin respective ends of said rails, said plugs having constructions thatare mirror images of each other, each of said plugs including a hollowbody received by interference press-fit into the hollow interior of theassociated rail end and an imperforate flat end wall at an angle of 45°to said body, said end walls extending outwardly from peripheries ofsaid bodies between said rail ends and having flat end faces that arewelded to each other.
 9. A method of joining mitered ends offiberglass-reinforced framing rails, which includes the steps of: (a)providing a pair of plugs, each of said plugs having a body and an endwall at an angle of 45° to said body, said plugs being of thermoplasticconstruction and of geometries that are mirror images of each other, (b)press fitting the bodies of said plugs into mitered ends of said railsso that the end walls of said plugs overlie the mitered ends of saidrails, and (c) bonding said end walls to each other.
 10. The method setforth in claim 9 wherein said step (c) is carried out by welding saidend walls to each other.
 11. The method set forth in claim 9 includingapplying a bonding agent to said bodies prior to said step (b).